October 21

1785 – Steamboat designer Henry Miller Shreve was born. In 1813, he built a steamboat which he dubbed the "Enterprise". The Enterprise made a journey from New Orleans to Pittsburgh.
1879 – Inventor Thomas A. Edison successfully demonstrates the first durable and commercially practical electric light bulb, at his laboratory in Menlo Park, New Jersey. The model lasted 40 hours before burning out.
1914 – Physicist and Engineer Samuel W. Alderson was born. Known for inventing the "crash test dummy," they were used in place of cadavers.
1959 – US President Dwight D. Eisenhower signs an executive order transferring German scientists from the control of the United States Army to NASA.
1978 – Australian civilian pilot Frederick Valentich vanishes over the Bass Strait south of Melbourne, after reporting contact with an unidentified aircraft (UFO).
2003 – Images of the dwarf planet Eris are taken, these photos subsequently are used in announcing its discovery.